I'm trying to figure out how I'm going to work my sling. I've got a Vltor Modstock, which has the QD swivel attachment near the buttplate, but I'd rather have a QD attachment point up at the front of the buffer tube/receiver extension. My castle nut is staked (as it should be) which means I'll either have to break the stakes loose to install a new receiver endplate or get one of the bolt on QD sling swivel adapters - such as the ones MI and DD are making.
Are there other manufacturer's making similar products?
Does anyone have one of these/experience with one of these?
I see three possible downsides:
Weight because they are bigger than the standard end plate replacements.
Possible rotation - not sure how/if each company designed around this.
Interference with the buffer/spring by possibly causing the receiver extension/buffer tube to be non-concentric since the thing is clamped on to it.

Your input is appreciated!

Thanks,
Austin